/**
 * Copyright (C) 2009 eXo Platform SAS.
 * 
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 * 
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.exoplatform.webui.application;

import org.exoplatform.web.application.Application;
import org.exoplatform.webui.Util;
import org.exoplatform.webui.config.Component;
import org.exoplatform.webui.core.UIComponent;
import org.exoplatform.webui.event.Event;
import org.exoplatform.webui.event.EventListener;

import java.io.InputStream;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

/**
 *Created by The eXo Platform SAS
 * May 7, 2006
 * 
 * This abstract class defines several methods to abstract the differnt type of web application the
 * eXo web framework can provide such as portal or portlet.
 */
abstract public class WebuiApplication extends Application
{

   private ConfigurationManager configManager_;

   private StateManager stateManager_;

   /**
    * This initialisation goals is to first extract and parse the webui configuration XML file 
    * defined inside the web.xml of the web application.
    * 
    * The ConfigurationManager class is responsible of the parsing and then wrap all the information 
    * about the UI configuration.
    * 
    * One of the information is the real implementation of the StateManager object. That object is 
    * extracted from the configuration and stored as a field in that class.
    * 
    * Lifecycle phases are also extracted from the XML file, referenced in this WebuiApplication class
    * and initialized at the same time.
    * 
    */
   public void onInit() throws Exception
   {
      String configPath = getApplicationInitParam("webui.configuration");
      InputStream is = getResourceResolver().getInputStream(configPath);
      configManager_ = new ConfigurationManager(is);
      String stateManagerClass = configManager_.getApplication().getStateManager();
      StateManager stManager = (StateManager)Util.createObject(stateManagerClass, null);
      setStateManager(stManager);
      setApplicationLifecycle(configManager_.getApplication().getApplicationLifecycleListeners());
      super.onInit();
   }

   public ConfigurationManager getConfigurationManager()
   {
      return configManager_;
   }

   public StateManager getStateManager()
   {
      return stateManager_;
   }

   public void setStateManager(StateManager sm)
   {
      stateManager_ = sm;
   }

   abstract public String getApplicationInitParam(String name);

   public <T> void broadcast(Event<T> event) throws Exception
   {
      List<EventListener> listeners = configManager_.getApplication().getApplicationEventListeners(event.getName());
      if (listeners == null)
         return;
      for (EventListener<T> listener : listeners)
         listener.execute(event);
   }

   public <T extends UIComponent> T createUIComponent(Class<T> type, String configId, String id,
      WebuiRequestContext context) throws Exception
   {
      Component config = configManager_.getComponentConfig(type, configId);
      if (config == null)
      {
         throw new Exception("Cannot find the configuration for the component " + type.getName() + ", configId "
            + configId);
      }
      T uicomponent = Util.createObject(type, config.getInitParams());
      uicomponent.setComponentConfig(id, config);
      return uicomponent;
   }

   public Set<UIComponent> getDefaultUIComponentToUpdateByAjax(WebuiRequestContext context)
   {
      Set<UIComponent> list = new LinkedHashSet<UIComponent>(3);
      list.add(context.getUIApplication());
      return list;
   }
}